Database layer

android/src/main/java/com/group14/regicidechess/android/AndroidLauncher.java

@@ -5,15 +5,20 @@
 import com.badlogic.gdx.backends.android.AndroidApplication;
 import com.badlogic.gdx.backends.android.AndroidApplicationConfiguration;
 import com.group14.regicidechess.Main;
+import com.group14.regicidechess.database.DatabaseManager;
 
 /** Launches the Android application. */
 public class AndroidLauncher extends AndroidApplication {
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
-        AndroidApplicationConfiguration configuration = new AndroidApplicationConfiguration();
-        configuration.useImmersiveMode = true; // Recommended, but not required.
-        initialize(new Main(new AndroidAPI()), configuration);
 
+        // Initialise Firebase bridge before starting the game
+        AndroidFirebase firebase = new AndroidFirebase();
+        DatabaseManager.getInstance().init(firebase);
+
+        AndroidApplicationConfiguration configuration = new AndroidApplicationConfiguration();
+        configuration.useImmersiveMode = true;
+        initialize(new Main(firebase), configuration);
     }
-}
+}

core/src/main/java/com/group14/regicidechess/Main.java

@@ -2,7 +2,7 @@
 
 import com.badlogic.gdx.Game;
 import com.badlogic.gdx.graphics.g2d.SpriteBatch;
-import com.group14.regicidechess.screens.MainMenuScreen;
+import com.group14.regicidechess.screens.mainmenu.MainMenuScreen;
 import com.group14.regicidechess.utils.ResourceManager;
 
 public class Main extends Game {

core/src/main/java/com/group14/regicidechess/database/DatabaseManager.java

@@ -0,0 +1,33 @@
+package com.group14.regicidechess.database;
+
+public class DatabaseManager {
+
+    private static DatabaseManager instance;
+    private FirebaseAPI api;
+
+    private DatabaseManager() {}
+
+    public static DatabaseManager getInstance() {
+        if (instance == null) instance = new DatabaseManager();
+        return instance;
+    }
+
+    public void init(FirebaseAPI api) {
+        this.api = api;
+    }
+
+    /**
+     * Returns the FirebaseAPI implementation.
+     * Throws a clear IllegalStateException if init() was never called,
+     * so the cause is obvious instead of a confusing NullPointerException.
+     */
+    public FirebaseAPI getApi() {
+        if (api == null) {
+            throw new IllegalStateException(
+                "DatabaseManager not initialised! " +
+                "Call DatabaseManager.getInstance().init(firebase) " +
+                "in your launcher before starting the game.");
+        }
+        return api;
+    }
+}

core/src/main/java/com/group14/regicidechess/database/FirebaseAPI.java

@@ -0,0 +1,82 @@
+package com.group14.regicidechess.database;
+
+import com.group14.regicidechess.model.Lobby;
+import com.group14.regicidechess.model.Move;
+
+public interface FirebaseAPI {
+
+    // ── Lobby ─────────────────────────────────────────────────────────────────
+
+    void createLobby(Lobby lobby, Callback<String> onSuccess, Callback<String> onError);
+    void joinLobby(String gameId, Callback<Lobby> onSuccess, Callback<String> onError);
+
+    /** Reads lobby settings without any side effects. Used by MainMenuScreen to validate. */
+    void fetchLobby(String gameId, Callback<Lobby> onSuccess, Callback<String> onError);
+
+    /**
+     * Fires once when lobbies/{gameId}/status == "joined".
+     * HOST calls this to know a second player has entered the lobby.
+     */
+    void listenForOpponentReady(String gameId, Runnable onReady);
+
+    /**
+     * Sets lobbies/{gameId}/status = "started".
+     * HOST calls this when pressing "Start Game" so the joiner navigates to SetupScreen.
+     */
+    void startGame(String gameId);
+
+    /**
+     * Fires once when lobbies/{gameId}/status == "started".
+     * JOINER calls this to know the host has pressed "Start Game".
+     */
+    void listenForGameStart(String gameId, Runnable onStart);
+
+    // ── Setup ─────────────────────────────────────────────────────────────────
+
+    /**
+     * Saves this player's board layout and marks them as setup-ready.
+     * Sets games/{gameId}/bothReady = true once BOTH players have called this.
+     */
+    void confirmSetup(String gameId, boolean isWhite, int[][] board, Runnable onSuccess);
+
+    /** Fetches the opponent's stored board layout. */
+    void getOpponentBoard(String gameId, boolean localIsWhite, Callback<int[][]> onBoard);
+
+    /**
+     * Fires once when games/{gameId}/bothReady == true.
+     * BOTH players call this in SetupScreen after confirming their boards.
+     * NOTE: Completely separate from listenForGameStart() which is lobby-phase only.
+     */
+    void listenForBothSetupReady(String gameId, Runnable onBothReady);
+
+    // ── In-match ──────────────────────────────────────────────────────────────
+
+    void saveMove(String gameId, Move move, Runnable onSuccess);
+
+    /**
+     * Fires for every move added to games/{gameId}/moves.
+     * Returns int[]{fromCol, fromRow, toCol, toRow, isWhite(1=white/0=black)}.
+     * Caller filters out own moves by comparing isWhite to localPlayer.isWhite().
+     */
+    void listenForOpponentMove(String gameId, Callback<int[]> onMove);
+
+    void sendHeartbeat(String gameId, boolean isWhite);
+
+    /**
+     * Listens for the opponent's heartbeat.
+     * @param onHeartbeat called with the latency (delay) in ms when a heartbeat arrives.
+     * @param onTimeout called if no heartbeat is received within timeoutMs.
+     */
+    void listenForHeartbeat(String gameId, boolean listenForWhite, long timeoutMs,
+                             Callback<Long> onHeartbeat, Runnable onTimeout);
+
+    /** e.g. "forfeit:white", "forfeit:black" */
+    void signalGameOver(String gameId, String reason);
+    void listenForGameOver(String gameId, Callback<String> onGameOver);
+
+    // ─────────────────────────────────────────────────────────────────────────
+
+    interface Callback<T> {
+        void call(T value);
+    }
+}

core/src/main/java/com/group14/regicidechess/model/Board.java

@@ -71,6 +71,10 @@ public ChessPiece movePiece(int fromCol, int fromRow, int toCol, int toRow) {
         ChessPiece moving   = removePiece(fromCol, fromRow);
         ChessPiece captured = pieces[toCol][toRow]; // may be null
         placePiece(moving, toCol, toRow);
+        // Notify pawn it has moved so the two-square rule is disabled next turn
+        if (moving instanceof com.group14.regicidechess.model.pieces.Pawn) {
+            ((com.group14.regicidechess.model.pieces.Pawn) moving).markMoved();
+        }
         return captured;
     }
 

core/src/main/java/com/group14/regicidechess/model/Move.java

@@ -10,6 +10,7 @@ public class Move {
     private final Vector2    to;
     private final ChessPiece piece;
     private final Player     player;
+    private String           promotion; // e.g. "Queen", "Rook", etc.
 
     public Move(Vector2 from, Vector2 to, ChessPiece piece, Player player) {
         this.from   = from.cpy();
@@ -18,8 +19,15 @@ public Move(Vector2 from, Vector2 to, ChessPiece piece, Player player) {
         this.player = player;
     }
 
-    public Vector2    getFrom()   { return from.cpy(); }
-    public Vector2    getTo()     { return to.cpy(); }
-    public ChessPiece getPiece()  { return piece; }
-    public Player     getPlayer() { return player; }
+    public Move(Vector2 from, Vector2 to, ChessPiece piece, Player player, String promotion) {
+        this(from, to, piece, player);
+        this.promotion = promotion;
+    }
+
+    public Vector2    getFrom()      { return from.cpy(); }
+    public Vector2    getTo()        { return to.cpy(); }
+    public ChessPiece getPiece()     { return piece; }
+    public Player     getPlayer()    { return player; }
+    public String     getPromotion() { return promotion; }
+    public void       setPromotion(String promotion) { this.promotion = promotion; }
 }

core/src/main/java/com/group14/regicidechess/model/pieces/Pawn.java

@@ -6,24 +6,30 @@
 import java.util.ArrayList;
 import java.util.List;
 
-/** Placement: core/src/main/java/com/group14/regicidechess/model/pieces/Pawn.java */
 public class Pawn extends ChessPiece {
 
+    private boolean hasMoved = false;
+
     public Pawn(Player owner) {
         super(owner, 1);
     }
 
     @Override
     public List<Vector2> validMoves() {
         List<Vector2> moves = new ArrayList<>();
-        // White moves up (+row), black moves down (-row)
         int dir = owner.isWhite() ? 1 : -1;
         int c = (int) position.x;
         int r = (int) position.y;
 
-        // Forward — only if square is empty (FR1.1)
+        // One square forward
         if (board.inBounds(c, r + dir) && board.getPieceAt(c, r + dir) == null) {
             moves.add(new Vector2(c, r + dir));
+
+            // Two squares forward on first move (FR1.2)
+            if (!hasMoved && board.inBounds(c, r + 2 * dir)
+                    && board.getPieceAt(c, r + 2 * dir) == null) {
+                moves.add(new Vector2(c, r + 2 * dir));
+            }
         }
 
         // Diagonal captures
@@ -36,9 +42,15 @@ public List<Vector2> validMoves() {
                 }
             }
         }
-        // No en passant (§2.1.3)
         return moves;
     }
 
+    /** Called by Board.movePiece() after the pawn is moved. */
+    public void markMoved() {
+        hasMoved = true;
+    }
+
+    public boolean hasMoved() { return hasMoved; }
+
     @Override public String getTypeName() { return "Pawn"; }
 }